Field
The present disclosure relates generally to an electronic device and a method of controlling a plurality of sensors connected through a network, and for example, to an electronic device and a method of efficiently controlling a plurality of sensors and reducing power consumption.
Description of Related Art
A virtual sensor allows sensor devices to be widely used on a network. To introduce the virtual sensor, there is a need of a server for collecting and processing physical sensing data. For example, there have been proposed a method of using a smartphone or the like user terminal as a virtual sensor server, a method of using an access point or the like gateway, a method of using a cloud server, etc. As compared with a mobile terminal device, the gateway sufficiently receives alternating current (AC) power or the like power, and gives high performance even though it additionally needs a networking operation between an application program and the virtual sensor. Further, the gateway has a shorter communication path and a shorter communication delay than those of the cloud server. These methods have something in common that they use a representational state transfer (REST) interface so that the virtual sensor can directly access all the sensor devices on the network through a uniform resource identifier (URI).
Power efficiencies of the sensor device and the user terminal are varied depending on methods of acquiring data from the sensor device. Technology about a method of acquiring sensing data has been proposed even before the appearance of an Internet of Things environment using the virtual sensor. The method of acquiring the sensing data according to the characteristics of the sensor device is broadly classified into polling and a push. The polling is a method that a user periodically reads data from the sensor, and the push is a method that the sensor sends data to a user when a specific event occurs in the sensor. Further, a push-based optimum method includes a model-driven method and a batching method. If the sensing data is not frequently processed, the batching method is advantageous since the sensing data is collected and then sent. If a slight change in the sensing data is ignorable, the model-driven method is advantageous since the sensing data is sent only when the sensing data is largely changed. However, if the sensor device does not support the batching method or the model-driven method in light of hardware, there may be no choice but to use the polling.
Further, the frequency of acquiring data is differently affected according to the methods of acquiring the sensing data. For example, the frequency of acquiring sensing data is determined based on a cycle of acquiring the sensing data in case of the polling, the number of pieces of sensing data to be sent at the same time in case of the batching method, or a threshold value for sending the sensing data in case of the model-driven method.
In particular, the Internet of Things environment involves more various kinds of sensor devices than the existing mobile environment, and thus different methods of acquiring the sensing data are used in accordance with the kinds of sensor to thereby increase power efficiencies. However, the method of acquiring the sensing data in the conventional virtual sensor technology does not increase the power efficiencies since it is limited to the REST interface, e.g., the operations of GET (polling) and OBSERVE (push).
In addition, there is a method of acquiring the sensing data even in Internet of Things environments where the virtual sensor is not used. However, this method merely controls a polling cycle, a network transfer cycle and the like frequency settings for acquiring the sensing data, or selects one among the methods of acquiring the sensing data, i.e. the polling, push and model-driven methods. However, such a change in only the method or frequency of acquiring the sensing data fails to meet a variety of Internet of Things sensor devices and a demand of the virtual sensor.